U.S. Pat. No. 3,860,121 relates to a replaceable metal bearing block which is removably fastened by welding to the butt end of a coupler shank. This particular metal bearing block is a narrow segment of a sphere and does not provide adequate coverage of a normally, convexly curved butt end of the coupler shank. Other portions of the butt end of the coupler shank are subject to wear which can eventually destory the coupler shank. The invention is directed to solving this problem by the provision of a highly improved wearplate for protecting the butt end of a coupler shank.
Briefly stated, the invention is in a coupler having a shank extending from the coupler head and terminating at a butt end which is normally convexly curved. In this case, the butt end is flat and provided with a configured recess which extends inwardly of the shank in the direction of the coupler head. A replaceable, non-metallic wearplate is disposed in the recess and has an outer convexly curved surface which corresponds to the normal curvature of a conventional butt end of a shank. The wearplate is provided with means for frictionally engaging the butt end of the shank to hold the wearplate in the recess.